When the length of the spring is 9.2cm how many kilograms does the suspended weight weigh

7 + (x/2) = 9.2

solve for x.

Step-by-step explanation:

We're hanging weights from a spring and measuring the distance of stretch. This is how those vegetable scales in grocery stores work (kind of). We know that the spring, with no weight, is 7 cm. So it can't get any shorter than this. We also know that for every kg of mass added, the spring stretches 0.5 cm. So, if you hung 3 kg of weight, the spring would have to stretch 0.5 * 3 = 1.5 cm. Add to that the 7 cm that it was originally and we have 8.5 cm of total length.

The second question is essentially answered by the first because the blank equation given in the first says

(initial length) + 1/2 * (mass added) = (total length)

The initial length will be a constant 7, the mass added we're told is to be x and the total length is to be y. Put those in their places and graph accordingly.

3) This is simply asking you to do what you've been doing, but in reverse. We have an equation, so we can now just plug in what we know and solve for what we don't.

7 + (x/2) = y

y = 9.2 in this case because it's representative of the total length, so we have

7 + (x/2) = 9.2

Now just solve for x.